FIELD OF THE INVENTION
The present invention relates to a transport system for the implementation of electrolytic deposition, coating or etching; and more particularly, relates to an apparatus for selective electrolytic metallization and deposition utilizing a fluid head arrangement. The invention is also directed to a method of making and maintaining an electrical contact with a product being processed in a transport system employed for selective electrolytic metallization and deposition, coating or etching. Furthermore, the invention is also directed to a method of making and maintaining an electrical contact with a product being processed as described herein, utilizing a fluid head arrangement.
A critical feature of any electrolytic process, particularly such as may be employed for the electrolytic metallization or deposition of metallic materials on a substrate is to be able to make good electrical contact with hardware on the substrate; for example, such as circuit boards, which are to be processed through the electrolytic metallization and deposition operation. In some instances, in order to implement the foregoing there is employed a type of well known apparatus employing a so-called fluid head design, incorporating electrodes which can be activated for implementing the metallization and deposition processes. Ordinarily, a fluid head does not readily enable the processing of discrete structures or product which are transported in separate parts or piecewise, but rather is adapted for processing continuous foils or webs forming the substrate, but which will still maintain electrical contact with each part. Processing with a fluid head is normally considered to be better suited to the implementing of reel to reel applications of the electrolytic metallization and deposition process, where a communing bar can be fabricated within the roll or web of material which is to be processed. However, without the capability of providing a continuous electrical contact, these processes are impossible to implement within the construction or format of a fluid head for individual printed circuit board processing.
Basically, conventional vertical or horizontal electrolytic metallization devices typically handle a standard, and very specific, size panel, in essence, a substrate, for their everyday production. When the size of the panel varies, especially in connection with processing with horizontal devices, ordinarily the device has to be shut down and the electrodes baffled so that the "active" area is retained within the size of the panel which is to be transported. This activity requires that the device be shut down completely, opened up and modified; which, in turn, has to be then implemented a second time in order to return to the original panel size. This results in a significant amount of non-productive downtime, as well as requiring engineering supervision. On panels with varying circuit densities, if processed by means of electro-pattern plating, there are also encountered problems with varying thickness in the deposition due to uniformity of the current density across the single large electrode which is typically employed in conventional platers.
Various structures are currently disclosed in the prior art or employed in carrying out an metallizing process, such as the electrolytic deposition onto a substrate of metallic materials, for example, such as copper in order to produce electrolytic copper foils through the employment of a rotating cathode drum and an anode or plurality of sub-anodes which are located opposite the cathode drum.
Kubo, et al., U.S. Pat. No. 5,326,455 discloses a method and an apparatus for the production of electrolytic copper foil, wherein the apparatus utilizes a bath rather than one or more fluid heads for plating the foil, or alternatively employs a plurality of anodes with a single fluid head. The individual anodes can be controlled with respect to the quantity of electricity being supplied so as to provide for a uniform electrolytic deposition of a metallic material across the foil surface.
Erickson et al., U.S. Pat. No. 5,389,214 discloses a fluid treatment system, wherein electrically reconfigurable electrode arrangements are employed, and in which a controller alters the effective separation area between the active electrode in response to resistivity variations so as to provide an optimal operation of the system. There is no workpiece provided for effectuating electrolytic deposition of metallic material, but rather the disclosure is directed to the treatment of fluids.
Blasing, et al., U.S. Pat. No. 5,292,424 pertains to a method for controlling a work cycle in electroplating plants, wherein different levels of electrical currents are applied to a series of adjacently located electrodes. This structure is similar in operation to Kubo, et al., U.S. Pat. No. 5,326,455 due to the utilization of baths in order to derive the electrolytic deposition of the metallic materials.
Komoto, et al., U.S. Pat. Nos. 4,749,460 and 4,765,878, each provide for an apparatus for electrolytic plating wherein the plating currents of a plurality of successive plating cells are automatically controlled in accordance with specific conditions in order to maintain uniform thickness of the metallic material which is being deposited onto a substrate.
Saprokhin, et al., U.S. Pat. No. 4,511,440 discloses a process for the electrolytic production of fluorine; however, in which there is no individual control of an electrical power supply to anodes. Furthermore, there is no disclosure of any workpiece which is coated through the deposition of a metallic material by means of electrolytic plating operation, and this publication is merely directed to the production of fluorine gas.
Schober, U.S. Pat. No. 4,164,454 discloses a continuous line for plating on intermittent lengths of metallic strip material, wherein workpieces are moved past a plating apparatus with no provision being made for any individual control of a supply of electrical current to the anodes.